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Background and Objectives: Disruption of the spine's sagittal balance is associated with significant negative impacts on quality of life. Compared with other spinal osteotomies, pedicle subtraction osteotomy (PSO), which can potentially offer greater correction, is considered technically challenging and performed at lower rates. The aim of this study was to review the use of PSO to correct fixed sagittal imbalance and assess its efficacy and associated perioperative complications., Methods: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the PubMed, EBSCO host, MEDLINE, and Google Scholar databases were queried for full-text English manuscripts published from 1961 to 2022, exploring PSO for the management of fixed sagittal imbalance. Studies were included if they reported preoperative and postoperative radiographic measurements. The mean Methodological Index for Nonrandomized Studies (MINORS) for included articles was 9.6 ± 1.1. The outcomes of interest included etiology, operative time, blood loss, complications, radiographic outcomes, and patient-reported outcomes. Statistical analysis was performed using a random-effects, inverse variance-weighted meta-analysis of observational data. Pre and postoperative radiographic and clinical outcomes were compared using a Student t -test., Results: Fourteen studies with 595 patients were included. Meta-analysis showed that the mean operative time was 7.2 ± 2.0 hours, and the average blood loss was 2033 ± 629 mL. After PSO, there was a significant improvement in sagittal vertebral axis (12.41-3.92 cm, P = .0003), LL (13.35°-42.60°, P = .000002), PSO angle (5.11° to -26.91°, P = .0001), and Oswestry Disability Index (55.36-27.35, P = .02). Common complications include pseudarthrosis (8.1%), neurological deficits (7.8%), and proximal junctional failure (6.0%)., Conclusion: PSO offers significant correction of sagittal vertebral axis, lumbar lordosis, PSO angle, and Oswestry Disability Index scores despite its reduced utilization in recent years. Blood loss and high complication rates must be considered when evaluating the efficacy of this procedure; however, surgeon experience and operative techniques can be used to reduce morbidity., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Objective: Patient-reported outcome measures (PROMs) are utilized to assess surgical success but are limited by data collection, response bias, and subjectivity. The large volume of digital healthcare data offers a new method to utilize healthcare utilization as a longitudinal, individualized, and objective proxy for health needs among surgical patients. This study aimed to design and evaluate a novel resource utilization in spine healthcare (RUSH) clustering method that complements PROMs in evaluating postoperative patient outcomes., Methods: This retrospective cross-sectional study conducted at a large, tertiary healthcare system included all adult patients undergoing cervical or lumbar surgery between 2014 and 2020 with at least 3 months follow-up. Postoperative healthcare utilization was analyzed using clinic visits, inpatient encounters, telephone encounters, MyChart messages, opioid use, physical therapy, injections, and imaging. Latent profile analysis determined RUSH clusters and changes in PROM Information System Physical Health (PROMIS-PH) scores preoperation and 12-months postoperation., Results: This study included 5602 surgeries (mean age 61.3 ± 13.1 years, 49.9% female). Four RUSH groups were identified: low utilizers (21.5%), moderate utilizers without advanced imaging (34.7%), moderate utilizers with advanced imaging (10.7%), and high utilizers (33.1%). Utilization patterns varied by surgery type, with lower-utilization patterns among non-fusion procedures and a consistent sub-population of high utilizers across all surgery types. High RUSH utilizers had the lowest pre-operative PROMIS-PH scores and the worst average postoperative change., Conclusions: RUSH clustering provides a novel, data-driven approach to measure surgical success, complementing traditional PROMs, and leveraging big data to monitor and respond to surgical outcomes., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Neurosurgery residency, known for its rigorous training, must adapt to evolving healthcare demands. Formal education should now encompass areas like quality improvement and patient safety, machine learning, career planning, research infrastructure, grant funding, and socioeconomics. We share our institution's experience with a yearlong enhanced didactics curriculum, complementing our traditional teaching., Methods: Our resident and faculty team evaluated essential skills for trainee success and leadership, identified knowledge gaps, and addressed them with 31 lectures. We conducted pre- and 6-month surveys using a Likert scale (1=strongly disagree, 3=neutral, 5=strongly agree) to assess resident education. Survey results were analyzed using Student t-tests, with P<0.05 indicating statistical significance., Results: Eleven out of 12 residents completed the pre- and 6-month surveys. The surveys revealed improved scores in areas such as research career preparation (3.0/5-4.33/5, P = 0.002), building research skills (3.18/5-4.33/5, P = 0.002), and comfort with quality and patient safety (4.09/5-4.75, P = 0.04). Residents found the lectures highly effective in supplementing their residency training (4.58/5). Qualitative feedback from faculty was highly positive as well., Conclusions: Organized neurosurgery excels in clinical and technical training for residents but lacks formalized training in crucial nonclinical areas, such as quality improvement and patient safety, machine learning/artificial intelligence, research infrastructure, and socioeconomics. Our formal curriculum focused on these topics, with positive resident engagement and feedback over the first six months. However, continuous longitudinal monitoring is needed to confirm the curriculum's efficacy. This program may guide other neurosurgery departments in enhancing resident education in these areas., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Posterior approach interbody fusion techniques such as posterior lumbar interbody fusion and transforaminal interbody fusion are known as the workhorse procedures for lumbar spinal fusion. Over the years, advancements in procedural steps, technique, and technology have sought to improve patient outcomes. Within the last 2 decades, considerable emphasis has been placed upon minimally invasive techniques utilizing tubular retractors and conscious sedation. Innovation in materials engineering, visualization technology such as endoscopes, and enabling technologies such as augmented reality and robotics have served to enhance the procedures and their outcomes., Competing Interests: Disclosure M P. Steinmetz receives royalties/honoraria from Globus, and speaker fees from Cerapedics. Authors A A. Patel, S. Srivatsa, and M A. Davison have no relevant disclosures., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background and Objectives: Return-to-work (RTW) is an important outcome for employed patients considering surgery for cervical spondylotic myelopathy (CSM). We conducted a post hoc analysis of patients as-treated in the Cervical Spondylotic Myelopathy Surgical Trial, a prospective, randomized trial comparing surgical approaches for CSM to evaluate factors associated with RTW., Methods: In the trial, patients were randomized (2:3) to either anterior surgery (anterior cervical decompression/fusion [ACDF]) or posterior surgery (laminoplasty [LP], or posterior cervical decompression/fusion [PCDF], at surgeon's discretion). Work status was recorded at 1, 3, 6, and 12 months postoperatively. For patients working full-time or part-time on enrollment, time to RTW was compared across as-treated surgical groups using discrete-time survival analysis. Multivariate logistic regression was used to assess predictors of RTW. Clinical outcomes were compared using a linear mixed-effects model., Results: A total of 68 (42%) of 163 patients were working preoperatively and were analyzed. In total, 27 patients underwent ACDF, 29 underwent PCDF, and 12 underwent LP. 45 (66%) of 68 patients returned to work by 12 months. Median time to RTW differed by surgical approach (LP = 1 month, ACDF = 3 months, PCDF = 6 months; P = .02). Patients with longer length-of-stay were less likely to be working at 1 month (odds ratio 0.51; 95% CI, 0.29-0.91; P = .022) and 3 months (odds ratio 0.39; 95% CI, 0.16-0.96; P = .04). At 3 months, PCDF was associated with lower Short-Form 36 physical component summary scores than ACDF (estimated mean difference [EMD]: 6.42; 95% CI, 1.4-11.4; P = .007) and LP (EMD: 7.98; 95% CI, 2.7-13.3; P = .003), and higher Neck Disability Index scores than ACDF (EMD: 12.48; 95% CI, 2.3-22.7; P = .01) and LP (EMD: 15.22; 95% CI, 2.3-28.1; P = .014), indicating worse perceived physical functioning and greater disability, respectively., Conclusion: Most employed patients returned to work within 1 year. LP patients resumed employment earliest, while PCDF patients returned to work latest, with greater disability at follow-up, suggesting that choice of surgical intervention may influence occupational outcomes., (Copyright © Congress of Neurological Surgeons 2024. All rights reserved.)

Background: Depression is common in spine surgery candidates and may influence postoperative outcomes. Ecological momentary assessments (EMAs) can overcome limitations of existing depression screening methods (e.g., recall bias, inaccuracy of historical diagnoses) by longitudinally monitoring depression symptoms in daily life. In this study, we compared EMA-based depression assessment with retrospective self-report (a 9-item Patient Health Questionnaire [PHQ-9]) and chart-based depression diagnosis in lumbar spine surgery candidates. We further examined the associations of each depression assessment method with surgical outcomes., Methods: Adult patients undergoing lumbar spine surgery (n = 122) completed EMAs quantifying depressive symptoms up to 5 times daily for 3 weeks preoperatively. Correlations (rank-biserial or Spearman) among EMA means, a chart-based depression history, and 1-time preoperative depression surveys (PHQ-9 and Psychache Scale) were analyzed. Confirmatory factor analysis was used to categorize PHQ-9 questions as somatic or non-somatic; subscores were compared with a propensity score-matched general population cohort. The associations of each screening modality with 6-month surgical outcomes (pain, disability, physical function, pain interference) were analyzed with multivariable regression., Results: The association between EMA Depression scores and a depression history was weak (r rb = 0.34 [95% confidence interval (CI), 0.14 to 0.52]). Moderate correlations with EMA-measured depression symptoms were observed for the PHQ-9 (r s = 0.51 [95% CI, 0.37 to 0.63]) and the Psychache Scale (r s = 0.68 [95% CI, 0.57 to 0.76]). Compared with the matched general population cohort, spine surgery candidates endorsed similar non-somatic symptoms but significantly greater somatic symptoms on the PHQ-9. EMA Depression scores had a stronger association with 6-month surgical outcomes than the other depression screening modalities did., Conclusions: A history of depression in the medical record is not a reliable indication of preoperative depression symptom severity. Cross-sectional depression assessments such as PHQ-9 have stronger associations with daily depression symptoms but may conflate somatic depression symptoms with spine-related disability. As an alternative to these methods, mobile health technology and EMAs provide an opportunity to collect real-time, longitudinal data on depression symptom severity, potentially improving prognostic accuracy., Level of Evidence: Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: This study was funded by grants from AO Spine North America, the Cervical Spine Research Society, the Scoliosis Research Society, the Foundation for Barnes-Jewish Hospital, the Washington University/BJC Healthcare Big Ideas Competition, and the National Institute of Mental Health (1F31MH124291-01A). The sponsors had no role in the study design, data collection, data interpretation, manuscript preparation, or decision to submit the manuscript for publication. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/I120 )., (Copyright © 2024 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: Bertolotti syndrome (BS) is characterized by chronic pain and functional impairment associated with lumbosacral transitional vertebrae (LSTVs). The study aimed to investigate the histologic characteristics of the pseudoarticulation between the enlarged transverse process and sacrum seen in Castellvi 2a LSTV and explore the involvement of nervous tissue in pain generation., Methods: Immunohistochemical analysis using S100 protein staining was performed to assess the presence of nerve tissue., Results: These changes included fibrillation, chondrocyte cloning, alterations in the proteoglycan matrix, and focal chondrocyte necrosis. Notably, no nerve tissue was observed in any of the specimens, as confirmed by negative S100 protein staining., Conclusions: The study findings suggest that nerve tissue is not involved in the nociceptive mechanisms underlying pain in BS. The histologic similarities between the pseudoarticulation and osteoarthritic joints indicate that pseudoarticulation itself may be a significant source of pain in BS. These insights contribute to our understanding of the pathophysiology of BS and support treatment paradigms prioritizing pain control with medications such as NSAIDs before considering surgical intervention. Future studies with larger sample sizes and in vivo models are needed to further validate these findings and explore the changes in joint histology under biomechanical forces in LSTVs., (Copyright © 2024. Published by Elsevier Inc.)

Study Design: Biomechanical cadaveric study., Objectives: Multi-rod constructs maximize posterior fixation, but most use a single pedicle screw (PS) anchor point to support multiple rods. Robotic navigation allows for insertion of PS and cortical screw (CS) within the same pedicle, providing 4 points of bony fixation per vertebra. Recent studies demonstrated radiographic feasibility for dual-screw constructs for posterior lumbar spinal fixation; however, biomechanical characterization of this technique is lacking., Methods: Fourteen cadaveric lumbar specimens (L1-L5) were divided into 2 groups (n = 7): PS, and PS + CS. VCF was simulated at L3. Bilateral posterior screws were placed from L2-L4. Load control (±7.5Nm) testing performed in flexion-extension (FE), lateral bending (LB), axial rotation (AR) to measure ROM of: (1) intact; (2) 2-rod construct; (3) 4-rod construct. Static compression testing of 4-rod construct performed at 5 mm/min to measure failure load, axial stiffness., Results: Four-rod construct was more rigid than 2-rod in FE ( P < .001), LB ( P < .001), AR ( P < .001). Screw technique had no significant effect on FE ( P = .516), LB ( P = .477), or AR ( P = .452). PS + CS 4-rod construct was significantly more stable than PS group ( P = .032). Stiffness of PS + CS group (445.8 ± 79.3 N/mm) was significantly greater ( P = .019) than PS (317.8 ± 79.8 N/mm). Similarly, failure load of PS + CS group (1824.9 ± 352.2 N) was significantly greater ( P = .001) than PS (913.4 ± 309.8 N)., Conclusions: Dual-screw, 4-rod construct may be more stable than traditional rod-to-rod connectors, especially in axial rotation. Axial stiffness and ultimate strength of 4-rod, dual-screw construct were significantly greater than rod-to-rod. In this study, 4-rod construct was found to have potential biomechanical benefits of increased strength, stiffness, stability., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: The comparative effectiveness of decompression plus lumbar facet arthroplasty versus decompression plus instrumented lumbar spinal fusion in patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis is unknown., Methods: In this randomized, controlled, Food and Drug Administration Investigational Device Exemption trial, we assigned patients who had single-level lumbar spinal stenosis and grade-I degenerative spondylolisthesis to undergo decompression plus lumbar facet arthroplasty (arthroplasty group) or decompression plus fusion (fusion group). The primary outcome was a predetermined composite clinical success score. Secondary outcomes included the Oswestry Disability Index (ODI), visual analog scale (VAS) back and leg pain, Zurich Claudication Questionnaire (ZCQ), Short Form (SF)-12, radiographic parameters, surgical variables, and complications., Results: A total of 321 adult patients were randomized in a 2:1 fashion, with 219 patients assigned to undergo facet arthroplasty and 102 patients assigned to undergo fusion. Of these, 113 patients (51.6%) in the arthroplasty group and 47 (46.1%) in the fusion group who had either reached 24 months of postoperative follow-up or were deemed early clinical failures were included in the primary outcome analysis. The arthroplasty group had a higher proportion of patients who achieved composite clinical success than did the fusion group (73.5% versus 25.5%; p < 0.001), equating to a between-group difference of 47.9% (95% confidence interval, 33.0% to 62.8%). The arthroplasty group outperformed the fusion group in most patient-reported outcome measures (including the ODI, VAS back pain, and all ZCQ component scores) at 24 months postoperatively. There were no significant differences between groups in surgical variables or complications, except that the fusion group had a higher rate of developing symptomatic adjacent segment degeneration., Conclusions: Among patients with lumbar spinal stenosis and grade-I degenerative spondylolisthesis, lumbar facet arthroplasty was associated with a higher rate of composite clinical success than fusion was at 24 months postoperatively., Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: This study was funded by Premia Spine (the manufacturer of the device being studied), which funded third-party data management and statistical analysis as well as the study coordinators at the study sites. The Article Processing Charge for open access publication was funded by Premia Spine. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H984 )., (Copyright © 2024 The Authors. Published by The Journal of Bone and Joint Surgery, Incorporated.)

Study Design: Retrospective quantitative analysis study., Objectives: Pelvic incidence has been established as central radiographic marker which determines patient-specific correction goals during surgery for adult spinal deformity. In cases with sacral doming or sacral osteotomy where the PI cannot be calculated, reliable radiographic parameters need to be established to determine surgical goals. We aim to determine multiple radiographic parameters and formulas that can be utilized when the S1 superior endplate is obscured., Methods: Retrospective analysis was performed on 68 healthy volunteers without prior spine surgery with full-length radiographs. Pelvic incidence, sacral slope, and pelvic tilt were calculated for each patient. Additional measurements such as L4, L5, and S2 incidence, tilt, and slope were collected. A new radiographic parameter defined as the L4-Sciatic notch angle was measured. Regression analysis was performed on each value to determine its relationship with S1 based incidence, tilt, and slope., Results: Mean values for L5 incidence, L4 incidence, and L4 sciatic notch angle were 21.8° ± 8.9, 4.4° ± 8.1, and 44.4° ± 12, respectively. The linear regression analysis produced the following formulas which can be utilized to determine deformity correction goals when pelvic incidence can be calculated pre-operatively: L5i = .65*S1i-11.4, L4i = .44*S1i-18.6, and L4SNA = -.34*S1i + 66.5. In settings where pelvic incidence cannot be calculated, the following formulas can be utilized: L5i = .66*S2i-32.3 and L4SNA = -.02*S2i 2 + 1.1*S2i + 63.5. P -values for all regression analyses were <.001., Conclusion: This study provides target radiographic alignment values that can be utilized for patients with either pre-operative altered S1 endplates or in cases with intraoperative alteration of S1 (sacral osteotomy)., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: The authors present a finite element analysis (FEA) evaluating the mechanical impact of C1-2 hypermobility on the spinal cord., Methods: The Code&#95;Aster program was used to perform an FEA to determine the mechanical impact of C1-2 hypermobility on the spinal cord. Normative values of Young's modulus were applied to the various components of the model, including bone, ligaments, and gray and white matter. Two models were created: 25° and 50° of C1-on-C2 rotation, and 2.5 and 5 mm of C1-on-C2 lateral translation. Maximum von Mises stress (VMS) throughout the cervicomedullary junction was calculated and analyzed., Results: The FEA model of 2.5 mm lateral translation of C1 on C2 revealed maximum VMS for gray and white matter of 0.041 and 0.097 MPa, respectively. In the 5-mm translation model, the maximum VMS for gray and white matter was 0.069 and 0.162 MPa. The FEA model of 25° of C1-on-C2 rotation revealed maximum VMS for gray and white matter of 0.052 and 0.123 MPa. In the 50° rotation model, the maximum VMS for gray and white matter was 0.113 and 0.264 MPa., Conclusions: This FEA revealed significant spinal cord stress during pathological rotation (50°) and lateral translation (5 mm) consistent with values found during severe spinal cord compression and in patients with myelopathy. While this finite element model requires oversimplification of the atlantoaxial joint, the study provides biomechanical evidence that hypermobility within the C1-2 joint leads to pathological spinal cord stress.

Introduction: Expandable devices such as interbody cages, vertebral body reconstruction cages, and intravertebral body expansion devices are frequently utilized in spine surgery. Since the introduction of expandable implants in the early 2000s, the variety of mechanisms that drive expansion and implant materials have steadily increased. By examining expandable devices that have achieved commercial success and exploring emerging innovations, we aim to offer an in-depth evaluation of the different types of expandable cages used in spine surgery and the underlying mechanisms that drive their functionality., Areas Covered: We performed a review of expandable spinal implants and devices by querying the National Library of Medicine MEDLINE database and Google Patents database from 1933 to 2024. Five major types of mechanical jacks that drive expansion were identified: scissor, pneumatic, screw, ratchet, and insertion-expansion., Expert Opinion: We identified a trend of screw jack mechanism being the predominant machinery in vertebral body reconstruction cages and scissor jack mechanism predominating in interbody cages. Pneumatic jacks were most commonly found in kyphoplasty devices. Critically reviewing the mechanisms of expansion and identifying trends among effective and successful cages allows both surgeons and medical device companies to properly identify future areas of development.

Tribology, an interdisciplinary field concerned with the science of interactions between surfaces in contact and their relative motion, plays a well-established role in the design of orthopedic implants, such as knee and hip replacements. However, its applications in spine surgery have received comparatively less attention in the literature. Understanding tribology is pivotal in elucidating the intricate interactions between metal, polymer, and ceramic components, as well as their interplay with the native human bone. Numerous studies have demonstrated that optimizing tribological factors is key to enhancing the longevity of joints and implants while simultaneously reducing complications and the need for revision surgeries in both arthroplasty and spinal fusion procedures. With an ever-growing and diverse array of spinal implant devices hitting the market for static and dynamic stabilization of the spine, it is important to consider how each of these devices optimizes these parameters and what factors may be inadequately addressed by currently available technology and methods. In this comprehensive review, the authors' objectives were twofold: 1) delineate the unique challenges encountered in spine surgery that could be addressed through optimization of tribological parameters; and 2) summarize current innovations and products within spine surgery that look to optimize tribological parameters and highlight new avenues for implant design and research.

Study Design: This is a cross-sectional survey., Objective: The aim was to assess the reliability of a proposed novel classification system for thoracic disc herniations (TDHs)., Summary of Background Data: TDHs are complex entities varying substantially in many factors, including size, location, and calcification. To date, no comprehensive system exists to categorize these lesions., Methods: Our proposed system classifies 5 types of TDHs using anatomic and clinical characteristics, with subtypes for calcification. Type 0 herniations are small (≤40% of spinal canal) TDHs without significant spinal cord or nerve root effacement; type 1 are small and paracentral; type 2 are small and central; type 3 are giant (>40% of spinal canal) and paracentral; and type 4 are giant and central. Patients with types 1 to 4 TDHs have correlative clinical and radiographic evidence of spinal cord compression. Twenty-one US spine surgeons with substantial TDH experience rated 10 illustrative cases to determine the system's reliability. Interobserver and intraobserver reliability were determined using the Fleiss kappa coefficient. Surgeons were also surveyed to obtain consensus on surgical approaches for the various TDH types., Results: High agreement was found for the classification system, with 80% (range 62% to 95%) overall agreement and high interrater and intrarater reliability (kappa 0.604 [moderate to substantial agreement] and kappa 0.630 [substantial agreement], respectively). All surgeons reported nonoperative management of type 0 TDHs. For type 1 TDHs, most respondents (71%) preferred posterior approaches. For type 2 TDHs, responses were roughly equivalent for anterolateral and posterior options. For types 3 and 4 TDHs, most respondents (72% and 68%, respectively) preferred anterolateral approaches., Conclusions: This novel classification system can be used to reliably categorize TDHs, standardize description, and potentially guide the selection of surgical approach. Validation of this system with regard to treatment and clinical outcomes represents a line of future study., Competing Interests: J.S.U. receives consulting fees and royalties from NuVasive, Inc, and is a consultant for Misonix, Inc, and SI-BONE, Inc. J.D.T. receives consulting fees and royalties from NuVasive, Inc. The remaining authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: The objective of this study was to gain a greater understanding of the burden of musculoskeletal disorders (MSDs) in spine surgeons, their impact on practice, and risk factors contributing to MSDs, including surgical instrument design and surgical ergonomics., Methods: An anonymous REDCap survey was distributed via email to the departments of several academic and private centers across the United States, as well as to the AANS/CNS Women in Neurosurgery Section email list. Chi-square tests and Wilcoxon rank-sum tests were used to compare responses by gender. Multivariable linear regression analysis was performed to identify predictors of discomfort in instrument utilization., Results: Survey responses were received from 120 spine surgeons (29.1% response rate), of which 73 were included in the analysis. A very high number of respondents had experienced an MSD (70.4%), 38.2% had undergone treatment for at least one MSD, and 13.4% had lost time at work for at least one MSD. Women were more likely than men to have lost time at work due to an MSD (22.6% vs 5.6%, p = 0.04). Women were more likely than men to report difficulty in instrument grip, comfort, and use on a 20-point Likert scale (mean 10.7 vs 15.2 points, p < 0.0001). This effect persisted when adjusting for glove size and days per week spent operating (p = 0.002). Specifically, women were less likely to agree that the handles of surgical instruments were an appropriate grip (p < 0.0001), that they rarely experienced difficulty when using them (p < 0.0001), and that they rarely needed to use two hands with instruments meant to be used with one hand (p = 0.0002)., Conclusions: The MSD burden in spine surgeons is substantial. While there was no evidence of gender differences in MSD rates and severity, female surgeons report significantly more discomfort with the use of surgical instruments. There is a need for more investigation of MSD risk factors in spine surgeons and mitigation strategies. Gender differences in comfort in instrument use should be further explored and addressed by spine surgeons and device manufacturers.

Importance: Comorbid depression is common among patients with degenerative lumbar spine disease. Although a well-researched topic, the evidence of the role of depression in spine surgery outcomes remains inconclusive., Objective: To investigate the association between preoperative depression and patient-reported outcome measures (PROMs) after lumbar spine surgery., Data Sources: A systematic search of PubMed, Cochrane Database of Systematic Reviews, Embase, Scopus, PsychInfo, Web of Science, and ClinicalTrials.gov was performed from database inception to September 14, 2023., Study Selection: Included studies involved adults undergoing lumbar spine surgery and compared PROMs in patients with vs those without depression. Studies evaluating the correlation between preoperative depression and disease severity were also included., Data Extraction and Synthesis: All data were independently extracted by 2 authors and independently verified by a third author. Study quality was assessed using Newcastle-Ottawa Scale. Random-effects meta-analysis was used to synthesize data, and I2 was used to assess heterogeneity. Metaregression was performed to identify factors explaining the heterogeneity., Main Outcomes and Measures: The primary outcome was the standardized mean difference (SMD) of change from preoperative baseline to postoperative follow-up in PROMs of disability, pain, and physical function for patients with vs without depression. Secondary outcomes were preoperative and postoperative differences in absolute disease severity for these 2 patient populations., Results: Of the 8459 articles identified, 44 were included in the analysis. These studies involved 21 452 patients with a mean (SD) age of 57 (8) years and included 11 747 females (55%). Among these studies, the median (range) follow-up duration was 12 (6-120) months. The pooled estimates of disability, pain, and physical function showed that patients with depression experienced a greater magnitude of improvement compared with patients without depression, but this difference was not significant (SMD, 0.04 [95% CI, -0.02 to 0.10]; I2 = 75%; P = .21). Nonetheless, patients with depression presented with worse preoperative disease severity in disability, pain, and physical function (SMD, -0.52 [95% CI, -0.62 to -0.41]; I2 = 89%; P < .001), which remained worse postoperatively (SMD, -0.52 [95% CI, -0.75 to -0.28]; I2 = 98%; P < .001). There was no significant correlation between depression severity and the primary outcome. A multivariable metaregression analysis suggested that age, sex (male to female ratio), percentage of comorbidities, and follow-up attrition were significant sources of variance., Conclusions and Relevance: Results of this systematic review and meta-analysis suggested that, although patients with depression had worse disease severity both before and after surgery compared with patients without depression, they had significant potential for recovery in disability, pain, and physical function. Further investigations are needed to examine the association between spine-related disability and depression as well as the role of perioperative mental health treatments.

Competing Interests: Declaration of Competing Interest One or more of the authors declare financial or professional relationships on ICMJE-TSJ disclosure forms.

Background: Despite the expanding role of machine learning (ML) in health care and patient expectations for clinicians to understand ML-based tools, few for-credit curricula exist specifically for neurosurgical trainees to learn basic principles and implications of ML for medical research and clinical practice. We implemented a novel, remotely delivered curriculum designed to develop literacy in ML for neurosurgical trainees., Methods: A 4-week pilot medical elective was designed specifically for trainees to build literacy in basic ML concepts. Qualitative feedback from interested and enrolled students was collected to assess students' and trainees' reactions, learning, and future application of course content., Results: Despite 15 interested learners, only 3 medical students and 1 neurosurgical resident completed the course. Enrollment included students and trainees from 3 different institutions. All learners who completed the course found the lectures relevant to their future practice as clinicians and researchers and reported improved confidence in applying and understanding published literature applying ML techniques in health care. Barriers to ample enrollment and retention (e.g., balancing clinical responsibilities) were identified., Conclusions: This pilot elective demonstrated the interest, value, and feasibility of a remote elective to establish ML literacy; however, feedback to increase accessibility and flexibility of the course encouraged our team to implement changes. Future elective iterations will have a semiannual, 2-week format, splitting lectures more clearly between theory (the method and its value) and application (coding instructions) and will make lectures open-source prerequisites to allow tailoring of student learning to their planned application of these methods in their practice and research., (Published by Elsevier Inc.)

Traumatic spinal cord injury exacerbates disability with time due to secondary injury cascade triggered largely by overproduction of reactive oxygen species (ROS) at the lesion site, causing oxidative stress. This study explored nanoparticles containing antioxidant enzymes (antioxidant NPs) to neutralize excess ROS at the lesion site and its impact. When tested in a rat contusion model of spinal cord injury, a single dose of antioxidant NPs, administered intravenously three hours after injury, effectively restored the redox balance at the lesion site, interrupting the secondary injury progression. This led to reduced spinal cord tissue inflammation, apoptosis, cavitation, and inhibition of syringomyelia. Moreover, the treatment reduced scar tissue forming collagen at the lesion site, protected axons from demyelination, and stimulated lesion healing, with further analysis indicating the formation of immature neurons. The ultimate effect of the treatment was improved motor and sensory functions and rapid post-injury weight loss recovery. Histological analysis revealed activated microglia in the spinal cord displaying rod-shaped anti-inflammatory and regenerative phenotype in treated animals, contrasting with amoeboid inflammatory and degenerative phenotype in untreated control. Overall data suggest that restoring redox balance at the lesion site shifts the dynamics in the injured spinal cord microenvironment from degenerative to regenerative, potentially by promoting endogenous repair mechanisms. Antioxidant NPs show promise to be developed as an early therapeutic intervention in stabilizing injured spinal cord for enhanced recovery., Competing Interests: Declaration of Competing Interest HJ and VL are co-inventors on the US (#11,439,690) and EU (#2953640) patents that cover antioxidant NPs and their use for treating spinal cord injury. The technology is licensed to AxoNeural Therapeutics, Inc., a spinout company of Cleveland Clinic. VL is the founder of the company. The Conflict of Interest Committee of Cleveland Clinic manages the conflict of interest as per its conflict of interest policies., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Objective: By 2030, the US will not have enough neurosurgeons to meet the clinical needs of its citizens. Replacement of neurosurgeons due to attrition can take more than a decade, given the time-intensive training process. To identify potential workforce retention targets, the authors sought to identify factors that might impact neurosurgeons' retirement considerations., Methods: The Council of State Neurosurgical Societies surveyed practicing AANS-registered neurosurgeons via email link to an online form with 25 factors that were ranked using a Likert scale of importance regarding retirement from the field (ranging from 1 for not important to 3 for very important). All participants were asked: "If you could afford it, would you retire today?", Results: A total of 447 of 3200 neurosurgeons (14%) responded; 6% had been in practice for less than 5 years, 19% for 6-15 years, 57% for 16-30 years, and 18% for more than 30 years. Practice types included academic (18%), hospital employed (31%), independent with academic appointment (9%), and full independent practice (39%). The most common practice size was between 2 and 5 physicians (46%), with groups of 10 or more being the next most common (20%). Career satisfaction, income, and the needs of patients were rated as the most important factors keeping neurosurgeons in the workforce. Increasing regulatory burden, decreasing clinical autonomy, and the burden of insurance companies were the highest rated for factors important in considering retirement. Subgroup analysis by career stage, practice size, practice type, and geographic region revealed no significant difference in responses. When considering if they would retire now, 45% of respondents answered "yes." Subgroup analysis revealed that midcareer neurosurgeons (16-25 years in practice) were more likely to respond "yes" than those just entering their careers or in practice for more than 25 years (p = 0.03). This effect was confirmed in multivariate logistic regression (p = 0.04). These surgeons found professional satisfaction (p = 0.001), recertification requirements (p < 0.001), and maintaining high levels of income (p = 0.008) important to maintaining employment within the neurosurgical workforce., Conclusions: This study demonstrates that midcareer neurosurgeons may benefit from targeted retention efforts. This effort should focus on maximizing professional satisfaction and financial independence, while decreasing the regulatory burden associated with certification and insurance authorization. End-of-career surgeons should be surveyed to determine factors contributing to resilience and persistence within the neurosurgical workforce.

Objective: In clinical spine surgery research, manually reviewing surgical forms to categorize patients by their surgical characteristics is a crucial yet time-consuming task. Natural language processing (NLP) is a machine learning tool used to adaptively parse and categorize important features from text. These systems function by training on a large, labeled data set in which feature importance is learned prior to encountering a previously unseen data set. The authors aimed to design an NLP classifier for surgical information that can review consent forms and automatically classify patients by the surgical procedure performed., Methods: Thirteen thousand two hundred sixty-eight patients who underwent 15,227 surgeries from January 1, 2012, to December 31, 2022, at a single institution were initially considered for inclusion. From these surgeries, 12,239 consent forms were classified based on the Current Procedural Terminology (CPT) code, categorizing them into 7 of the most frequently performed spine surgeries at this institution. This labeled data set was split 80%/20% into train and test subsets, respectively. The NLP classifier was then trained and the results demonstrated its performance on the test data set using CPT codes to determine accuracy., Results: This NLP surgical classifier had an overall weighted accuracy rate of 91% for sorting consents into correct surgical categories. Anterior cervical discectomy and fusion had the highest positive predictive value (PPV; 96.8%), whereas lumbar microdiscectomy had the lowest PPV in the testing data (85.0%). Sensitivity was highest for lumbar laminectomy and fusion (96.7%) and lowest for the least common operation, cervical posterior foraminotomy (58.3%). Negative predictive value and specificity were > 95% for all surgical categories., Conclusions: Utilizing NLP for text classification drastically improves the efficiency of classifying surgical procedures for research purposes. The ability to quickly classify surgical data can be significantly beneficial to institutions without a large database or substantial data review capabilities, as well as for trainees to track surgical experience, or practicing surgeons to evaluate and analyze their surgical volume. Additionally, the capability to quickly and accurately recognize the type of surgery will facilitate the extraction of new insights from the correlations between surgical interventions and patient outcomes. As the database of surgical information grows from this institution and others in spine surgery, the accuracy, usability, and applications of this model will continue to increase.

Competing Interests: M.P.S.—Zimmer Biomet and G.D.S.—Stryker, Zimmer Biomet. G.D.S. has received funds to travel from AOSpine and Medtronic. The remaining authors declare no conflict of interest.

Background: The increase in use of targeted systemic therapies in cancer treatments has catalyzed the importance of identifying patient- and tumor-specific somatic mutations, especially regarding metastatic disease. Mutations found to be most prevalent in patients with metastatic breast cancer include TP53, PI3K, and CDH1., Objective: To determine the incidence of somatic mutations in patients with metastatic breast cancer to the spine (MBCS). To determine if a difference exists in overall survival (OS), progression-free survival, and progression of motor symptoms between patients who do or do not undergo targeted systemic therapy after treatment for MBCS., Methods: This is a retrospective study of patients with MBCS. Review of gene sequencing reports was conducted to calculate the prevalence of various somatic gene mutations within this population. Those patients who then underwent treatment (surgery/radiation) for their diagnosis of MBCS between 2010 and 2020 were subcategorized. The use of targeted systemic therapy in the post-treatment period was identified, and post-treatment OS, progression-free survival, and progression of motor deficits were calculated for this subpopulation., Results: A total of 131 patients were included in the final analysis with 56% of patients found to have a PI3K mutation. Patients who received targeted systemic therapies were found to have a significantly longer OS compared with those who did not receive targeted systemic therapies., Conclusion: The results of this study demonstrate that there is an increased prevalence of PI3K mutations in patients with MBCS and there are a significant survival benefit and delay in progression of motor symptoms associated with using targeted systemic therapies for adjuvant treatment., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Objective: The American Spine Registry (ASR) is a collaborative effort between the American Academy of Orthopaedic Surgeons and the American Association of Neurological Surgeons. The goal of this study was to evaluate how representative the ASR is of the national practice with spinal procedures, as recorded in the National Inpatient Sample (NIS)., Methods: The authors queried the NIS and the ASR for cervical and lumbar arthrodesis cases performed during 2017-2019. International Classification of Diseases, 10th Revision and Current Procedural Terminology codes were used to identify patients undergoing cervical and lumbar procedures. The two groups were compared for the overall proportion of cervical and lumbar procedures, age distribution, sex, surgical approach features, race, and hospital volume. Outcomes available in the ASR, such as patient-reported outcomes and reoperations, were not analyzed due to nonavailability in the NIS. The representativeness of the ASR compared to the NIS was assessed via Cohen's d effect sizes, and absolute standardized mean differences (SMDs) of < 0.2 were considered trivial, whereas > 0.5 were considered moderately large., Results: A total of 24,800 arthrodesis procedures were identified in the ASR for the period between January 1, 2017, and December 31, 2019. During the same time period, 1,305,360 cases were recorded in the NIS. Cervical fusions comprised 35.9% of the ASR cohort (8911 cases) and 36.0% of the NIS cohort (469,287 cases). The two databases presented trivial differences in terms of patient age and sex for all years of interest across both cervical and lumbar arthrodeses (SMD < 0.2). Trivial differences were also noted in the distribution of open versus percutaneous procedures of the cervical and lumbar spine (SMD < 0.2). Among lumbar cases, anterior approaches were more common in the ASR than in the NIS (32.1% vs 22.3%, SMD = 0.22), but the discrepancy among cervical cases in the two databases was trivial (SMD = 0.03). Small differences were illustrated in terms of race, with SMDs < 0.5, and a more significant discrepancy was identified in the geographic distribution of participating sites (SMDs of 0.7 and 0.74 for cervical and lumbar cases, respectively). For both of these measures, SMDs in 2019 were smaller than those in 2018 and 2017., Conclusions: The ASR and NIS databases presented a very high similarity in proportions of cervical and lumbar spine surgeries, as well as similar distributions of age and sex, and distribution of open versus endoscopic approach. Slight discrepancies in anterior versus posterior approach among lumbar cases and patient race, and more significant discrepancies in geographic representation were also identified, yet decreasing trends in differences suggested the improving representativeness of the ASR over the course of time and its progressive growth. These conclusions are important to underline the external validity of quality investigations and research conclusions to be drawn from analyses in which the ASR is used.

Objective: Neurosurgery program websites serve as a valuable resource for applicants. However, each website exists in isolation, and it can be difficult to understand the general trends in U.S. neurosurgery resident demographics. In the present study, we collected data from program websites and analyzed the trends in the demographics of the current U.S. neurosurgery residents., Methods: We used a program list obtained from the American Association of Medical Colleges Electronic Residency Application System to extract data from the current resident complement listed in each program's website, including program, year in program, medical school, sex (male vs. female), graduate and/or PhD degrees, and assessed the trends during 7 years of resident data using linear regression., Results: We identified 116 neurosurgery residency programs in the United States, with 111 providing information on their current resident complement, yielding a dataset of 1599 residents. Of these 1599 residents, 348 (22%) were female, 301 (19%) had a graduate degree in addition to an MD or DO degree, 151 (9.4%) had a PhD degree, 300 (19%) had matched at the program affiliated with their medical school, and 121 (7.6%) had graduated from a foreign medical school. The proportion of matriculating female residents had increased an average of 2.1% annually (95% confidence interval, 0.6%-3.7%) from 2015 to 2021. The other demographic data had not changed significantly during the same period., Conclusions: In addition to summarizing the current resident demographics, our analysis identified a significant increase in the proportion of female residents between 2015 (15.1%) and 2021 (25.6%). This publicly available dataset should enable additional analyses of the evolution of neurosurgery resident demographics., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: Bertolotti syndrome is a clinical diagnosis given to patients with low-back pain arising from a lumbosacral transitional vertebra (LSTV). While biomechanical studies have demonstrated abnormal torques and range of motion occurring at and above this type of LSTV, the long-term effects of these biomechanical changes on the LSTV adjacent segments are not well understood. This study examined degenerative changes at segments superjacent to the LSTV in patients with Bertolotti syndrome., Methods: This study involved a retrospective comparison of patients between 2010 and 2020 with an LSTV and chronic back pain (Bertolotti syndrome) and control patients with chronic back pain with no LSTV. The presence of an LSTV was confirmed on imaging, and the caudal-most mobile segment above the LSTV was assessed for degenerative changes. Degenerative changes were assessed by grading the intervertebral disc, facets, degree of spinal stenosis, and spondylolisthesis using well documented grading systems. All computations were performed in R, version 4.1.0. All tests were two-sided, and p values < 0.05 was considered statistically significant. Separate logistic regression analyses were run with the associated dependent variables for each aim, with age at MRI and sex included as covariates. Odds ratios and 95% confidence intervals were computed., Results: A total of 172 patients were included, 101 with Bertolotti syndrome and 71 controls. Control patients consisted of patients with low-back pain but no diagnosis of Bertolotti syndrome or an LSTV. Fifty-six Bertolotti (55.4%) and 27 control (38.0%) patients were female, (p = 0.03). After adjusting for age at MRI and sex, Bertolotti patients had pelvic incidence (PI) that was 9.83° greater than control patients (95% CI 5.15°-14.50°, p < 0.001). Sacral slope was not significantly different between the Bertolotti and control groups (beta estimate 3.10°, 95% CI -1.07° to 7.27°; p = 0.14). Bertolotti patients had 2.69 times higher odds of having a high disc grade at L4-5 (3-4 vs 0-2), compared with control patients (OR 2.69, 95% CI 1.28-5.90; p = 0.01). There were no significant differences between Bertolotti patients and controls for spondylolisthesis, facet grade, or spinal stenosis grade., Conclusions: Patients with Bertolotti syndrome had a significantly higher PI and were more likely to have adjacent-segment disease (ASD; L4-5) compared with control patients. However, after controlling for age and sex, PI and ASD did not appear to have a significant association within the cohort of Bertolotti patients. The altered biomechanics and kinematics in this condition may be a causative factor in this degeneration, although proof of causation is not possible in this study. This association may warrant closer follow-up protocols for patients being treated for Bertolotti syndrome, but further prospective studies are needed to establish if radiographic parameters can serve as an indicator for biomechanical alterations in vivo.

Study Design: Prospective randomized Food and Drug Administration investigational device exemption clinical trial., Objective: The purpose of the present study is to report the 1-year clinical and radiographic outcomes and safety profile of patients who underwent lumbar facet arthroplasty through implantation of the Total Posterior Spine System (TOPS) device., Summary of Background Data: Lumbar facet arthroplasty is one proposed method of dynamic stabilization to treat grade-1 spondylolisthesis with stenosis; however, there are currently no Food and Drug Administration-approved devices for facet arthroplasty., Methods: Standard demographic information was collected for each patient. Radiographic parameters and patient-reported outcome measures were assessed preoperatively and at regular postoperative intervals. Complication and reoperation data were also collected for each patient., Results: At the time of this study, 153 patients had undergone implantation of the TOPS device. The mean surgical time was 187.8 minutes and the mean estimated blood loss was 205.7cc. The mean length of hospital stay was 3.0 days. Mean Oswestry Disability Index, Visual Analog Score leg and back, and Zurich Claudication Questionnaire scores improved significantly at all postoperative time points ( P >0.001). There were no clinically significant changes in radiographic parameters, and all operative segments remained mobile at 1-year follow-up. Postoperative complications occurred in 11 patients out of the 153 patients (7.2%) who underwent implantation of the TOPS device. Nine patients (5.9%) underwent a total of 13 reoperations, 1 (0.6%) of which was for device-related failure owing to bilateral L5 pedicle screw loosening., Conclusions: Lumbar facet arthroplasty with the TOPS device demonstrated a statistically significant improvement in all patient-reported outcome measures and the ability to maintain motion at the index level while limiting sagittal translation with a low complication rate., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc.)

Objective: The US-based Spinal Laminectomy versus Instrumented Pedicle Screw (SLIP) trial reported improvement in disability following laminectomy with fusion versus laminectomy alone for patients with lumbar spondylolisthesis. Despite using similar methods, a concurrent Swedish trial investigating the same question did not reach the same conclusion. The authors performed a simulation-based analysis to elucidate potential causes of these divergent results., Methods: The mean and standard deviation of the preoperative and 2-year postoperative Oswestry Disability Index (ODI) scores for each study group (laminectomy with fusion and laminectomy alone) were collected from the spondylolisthesis stratum of the Swedish trial and used to create a MATLAB simulator using linear transformations to predict postoperative ODI distributions. Applying this simulator to both varied and published preoperative ODI distributions from the SLIP trial, the authors simulated the results of the US-based trial using treatment effects from the Swedish study and compared simulated US results to those published in the SLIP trial., Results: Simulated US results showed that as preoperative disability increased, the difference in postoperative ODI scores grew between treatment groups and increasingly favored laminectomy alone (p < 0.0001). In 100 simulations of a similarly sized US trial, the average mean change in ODI scores postoperatively was significantly higher than was published for laminectomy alone in the SLIP trial (-21.3 vs -17.9), whereas it was significantly lower than published for fusion (-16.9 vs -26.3)., Conclusions: The expected benefit of surgical treatments for spondylolisthesis varied according to preoperative disability. Adapting Swedish-estimated treatment effects to the US context mildly overapproximated the improvement in postoperative disability scores for laminectomy, but more severely underapproximated the improvement reported for laminectomy and fusion in the SLIP trial. The observed heterogeneity between these studies is influenced more by patient response to fusion than response to laminectomy. This analysis paves the way for future studies on the impact of preoperative treatment group heterogeneity, differences in surgical methods, and empirical design on reported clinical benefits. Although bayesian reanalysis of published randomized controlled trial data is susceptible to biases that typically limit post hoc analyses, the authors' method offers a simple and cost-effective approach to improve the understanding of published clinical trial results and their implications for future studies.

Interviews are critical to the neurosurgery resident application process. The COVID-19 pandemic forced residency interview activities are conducted virtually. To maintain a degree of control during a period of uncertainty, our department implemented a standardized survey for interviewers to evaluate the noncognitive attributes and program compatibility of applicants. Our objective was to assess the reliability and biases associated with our standardized interviewer survey implemented in neurosurgical residency interviews. A 5-question interviewer survey to assess applicant interview performance and program compatibility was implemented during the 2020 to 2021 interview season. After the application cycle, survey metrics were retrospectively reviewed. Multiple cohort analyses were performed by dividing interviewers into cohorts based on status (faculty or resident) and sex. Applicant scores were assessed within sex subgroups for each aforementioned interviewer cohort. Intraclass correlation coefficients (ICCs) were calculated to assess survey reliability. Fifteen interviewers (8 faculty and 7 residents) and 35 applicants were included. Female applicants (17%) and interviewers (20%) comprised the minority. There were no differences between resident and faculty reviewer scores; however, female reviewers gave higher overall scores than male reviewers ( P = .003). There was no difference in total scores between female and male applicants when evaluating all reviewers or subgroups of faculty, residents, females, or males. ICC analysis demonstrated good (ICC 0.75-0.90) or excellent (ICC > 0.90) reliability for all questions and overall score. The standardized interviewer survey was a feasible and reliable method for evaluating noncognitive attributes during neurosurgery residency interviews. There was no perceptible evidence of sex bias in our single-program experience., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

Purpose: The Modified Low Back Pain Disability Questionnaire (MDQ) is a commonly used tool to assess functioning of patients with low back pain (LBP). Recently, the Patient-Reported Outcomes Measurement Information System (PROMIS) was suggested as an alternative platform to assess LBP patient-reported health. We sought to map between the MDQ and PROMIS Physical Function (PROMIS-PF) and Pain Interference (PROMIS-PI) scales using multiple methods., Methods: In a retrospective analysis of LBP patients seen at Cleveland Clinic 11/14/18-12/11/19, T-scores from each PROMIS scale were mapped to MDQ total score individually and together. MDQ item and total scores were mapped to each PROMIS scale. Linear regression as well as linear and equipercentile equating were used. Split sample internal validation using root mean squared error (RMSE), mean absolute error (MAE), and correlations were used to assess accuracy of mapping equations., Results: 13585 patients completed the three scales. In the derivation cohort, average age was 59.0 (SD = 15.8); 53.3% female and 82.9% white. Average MDQ total, PROMIS-PF, and PROMIS-PI T-scores were 40.3 (SD = 19.0), 37.2 (SD = 7.6), and 62.9 (SD = 7.2), respectively. For estimating MDQ total scores, methods that used both PROMIS-PF and PROMIS-PI had closest estimated means, lowest RMSE and MAE, and highest correlations. For estimating each of PROMIS-PF and PROMIS-PI T-scores, the best performing method was equipercentile equating using the MDQ items., Conclusions: We created and internally validated maps between MDQ and PROMIS-PF and PROMIS-PI using linear regression, linear and equipercentile equating. Our equations can be used by researchers wishing to translate scores between these scales., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background & Importance: This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward., Methods: The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions., Results: Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic., Discussion & Conclusion: DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed., Competing Interests: Dr. Palackdharry: none Stephanie Wottrich: none. Dr. Dienes: none. Dr. Bydon: none Dr. Steinmetz: Elsevier: royalties; Globus: consultant; Medtronic: honorarium; Zimmer Biomet: royalties. Dr. Traynelis: Medtronic: consultant, royalties; NuVasive: consultant This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Objective: The purpose of this study was to evaluate the safety and efficacy of a posterior facet replacement device, the Total Posterior Spine (TOPS) System, for the treatment of one-level symptomatic lumbar stenosis with grade I degenerative spondylolisthesis. Posterior lumbar arthroplasty with facet replacement is a motion-preserving alternative to lumbar decompression and fusion. The authors report the preliminary results from the TOPS FDA investigational device exemption (IDE) trial., Methods: The study was a prospective, randomized controlled FDA IDE trial comparing the investigational TOPS device with transforaminal lumbar interbody fusion (TLIF) and pedicle screw fixation. The minimum follow-up duration was 24 months. Validated patient-reported outcome measures included the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain. The primary outcome was a composite measure of clinical success: 1) no reoperations, 2) no device breakage, 3) ODI reduction of ≥ 15 points, and 4) no new or worsening neurological deficit. Patients were considered a clinical success only if they met all four measures. Radiographic assessments were made by an independent core laboratory., Results: A total of 249 patients were evaluated (n = 170 in the TOPS group and n = 79 in the TLIF group). There were no statistically significant differences between implanted levels (L4-5: TOPS, 95% and TLIF, 95%) or blood loss. The overall composite measure for clinical success was statistically significantly higher in the TOPS group (85%) compared with the TLIF group (64%) (p = 0.0138). The percentage of patients reporting a minimum 15-point improvement in ODI showed a statistically significant difference (p = 0.037) favoring TOPS (93%) over TLIF (81%). There was no statistically significant difference between groups in the percentage of patients reporting a minimum 20-point improvement on VAS back pain (TOPS, 87%; TLIF, 64%) and leg pain (TOPS, 90%; TLIF, 88%) scores. The rate of surgical reintervention for facet replacement in the TOPS group (5.9%) was lower than the TLIF group (8.8%). The TOPS cohort demonstrated maintenance of flexion/extension range of motion from preoperatively (3.85°) to 24 months (3.86°)., Conclusions: This study demonstrates that posterior lumbar decompression and dynamic stabilization with the TOPS device is safe and efficacious in the treatment of lumbar stenosis with degenerative spondylolisthesis. Additionally, decompression and dynamic stabilization with the TOPS device maintains segmental motion.

Background Context: Primary malignant non-osseous spinal tumors are relatively rare and this has led to a paucity of studies specifically examining the epidemiology of malignant spinal tumors., Purpose: To provide an updated and more comprehensive study examining the epidemiology and relative survival of these rare tumors., Study Design/setting: Data was retrospectively acquired from the Central Brain Tumor Registry of the United States (CBTRUS)., Patient Sample: Primary malignant non-osseous spinal tumor cases diagnosed between 2000 and 2017 in the United States., Outcome Measures: Incidence rates (IRs), relative survival rates, and hazard ratios (HR) were measured., Methods: IRs were calculated only for histologically-confirmed cases between 2000 and 2017. Relative survival estimates were calculated from survival information on malignant spinal tumors between 2001 and 2016 for death from any cause. Multivariable Cox proportional hazards regression models were constructed to control for age, sex, race, and ethnicity., Results: From 2000 to 2017, approximately 587 new cases of malignant non-osseous spinal tumors were diagnosed every year in the United States. The overall IR was 0.178 per 100,000 persons. Ependymomas were the most commonly diagnosed tumor in all age groups. The 10-year relative survival rates were 94.1%, 62.1%, 62.0%, and 13.3% for ependymomas, lymphomas, diffuse astrocytomas, and high-grade astrocytomas, respectively. Females have a significantly lower risk of death as compared with males for ependymomas (HR: 0.74, p<.001) and diffuse astrocytomas (HR: 0.70, p=.005). African-Americans have a significantly higher risk of death compared with Caucasians when diagnosed with ependymomas (HR: 1.52, p=.009) or lymphomas (HR: 1.55, p=.009)., Conclusion: Primary malignant non-osseous spinal tumors are primarily diagnosed in adulthood or late adulthood. Ependymal tumors are the most commonly diagnosed primary malignant non-osseous spinal tumors and have the highest 10-year relative survival rates. High-grade astrocytomas are rare and portend the worst prognosis., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background Context: Bertolotti syndrome is a clinical diagnosis given to patients with back pain arising from a lumbosacral transitional vertebra (LSTV). A particular class of LSTV involves a pseudoarticulation between the fifth lumbar transverse process and the sacral ala, and surgical resection of the pseudoarticulation may be offered to patients failing conservative management. Bertolotti syndrome is still not well understood, particularly regarding how patients respond to surgical resection of the LSTV pseudoarticulation., Purpose: To examine change in quality-of-life (QOL) and patient satisfaction following surgical resection of the LSTV pseudoarticulation in patients with Bertolotti syndrome., Design: Ambidirectional observational cohort study of patients seen at a single institution's tertiary spine center over a 10-year period., Patient Sample: Cohort consisted of 31 patients with Bertolotti Syndrome who underwent surgical resection of the pseudoarticulation., Outcome Measures: Preoperative and postoperative Patient-Reported Outcomes Measurement Information System Global Health (PROMIS-GH) Mental and Physical Health T-scores, and a single-item postoperative satisfaction questionnaire., Methods: Patients were identified through diagnostic and procedural codes. Immediate preoperative PROMIS-GH scores available in the chart were gathered retrospectively, and postoperative PROMIS-GH and satisfaction scores were gathered prospectively through a mail-in survey., Results: Mean (SD) improvement of PROMIS-GH Physical Health T-score was 8.7 (10.5) (p<.001). Mean (SD) improvement of PROMIS-GH Mental Health T-scores was 5.9 (9.2) (p=.001). When stratifying PROMIS-GH T-scores by response to the patient satisfaction survey, there were significant group differences in mean change for Physical Health T-scores (p<.001), and Mental Health T-score (p=.009). Patients who stated, "The treatment met my expectations" had much greater mean improvement in the PROMIS-GH T-scores., Conclusions: Patients undergoing a pseudoarticulation resection procedure may experience a significant improvement in quality-of-life as measured by PROMIS-GH Mental and Physical Health., Competing Interests: Declaration of competing interest This project received no financial support of any kind. The authors have no relevant disclosures or conflicts of interest to report., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: There is a paucity of evidence describing the price information that is publicly available to patients wishing to undergo neurosurgical procedures. We sought to investigate the public availability and usefulness of price estimates for non-emergent, elective neurosurgical interventions., Methods: Google was used to search for price information related to 15 procedures in 8 major U.S. health care markets. We recorded price information that was published for each procedure and took note of whether itemized prices, potential discounts, and cross-provider price comparisons were available., Results: Online searches yielded 2356 websites, of which 228 (9.7%) offered geographically relevant price information for neurosurgical procedures. Although accounting for only 16.4% of total search results, price transparency websites provided most treatment price estimates (74.1% of all estimates), followed by clinical sites (19.3%), and other related sites (5.3%). The number of websites providing price information varied significantly by city and procedure. websites rarely divulged data sources, specified how prices were estimated, indicated how frequently price estimates were updated, offered itemized breakdowns of prices, or indicated whether price estimates encompassed the full spectrum of possible health care charges., Conclusions: Under 10% of websites queried yield geographically relevant price information for non-emergent neurosurgical imaging and operative procedures. Even when this information is publicly available, its usefulness to patients may be limited by various factors, including obscure data sources and methods, as well as sparse information on discounts and bundled price estimates. Inconsistent availability and clarity of price information likely impede patients' ability to discern expected costs of treatment and engage in cost-conscious, value-based neurosurgical decision-making., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objective: Bertolotti syndrome is a diagnosis given to patients experiencing low-back pain due to a lumbosacral transitional vertebra (LSTV). LSTVs cause altered biomechanics at the lumbosacral junction, predisposing these patients to degenerative disease. It has been proposed that these patients have additional non-osseous variation such as ligamentous differences in the lumbar spine. The iliolumbar ligament, which attaches from the iliac crest to the transverse process of L4 and L5, plays a significant role in reducing lumbar motion in all six degrees of freedom; therefore, altered ligament anatomy can have a significant impact on stability. The purpose of this study was to examine the iliolumbar ligament complex in patients with Bertolotti syndrome and anatomically normal controls to determine if underdevelopment of the iliolumbar ligament complex is seen in Bertolotti syndrome., Methods: This is a retrospective analysis of patients with Bertolotti syndrome and anatomically normal controls who received care at the authors' institution between 2010 and 2020. Axial thickness of the iliolumbar ligament at the L5 vertebral level was assessed via MRI. Results were compared between the defective and normal side within unilaterally affected (Castellvi types IIa and IIIa) Bertolotti syndrome patients, between defective sides in bilaterally affected Bertolotti syndrome patients (Castellvi types IIb, IIIb, and IV), and between the affected side in Bertolotti syndrome patients and the corresponding location in normal controls., Results: A total of 173 patients were included in the study, 102 with Bertolotti syndrome and 71 controls. Among the Bertolotti patients, 49 had left LSTVs, 29 had right LSTVs, and 24 had bilateral LSTVs. For patients with unilateral defects, defective side ligaments were thinner than ligaments on the normal side (p < 0.05). For bilateral LSTVs, ligament thickness on each side was considered statistically equivalent (p < 0.05) and not significantly different from that in controls., Conclusions: Bertolotti syndrome correlates to significant underdevelopment of the iliolumbar ligament corresponding to the side of the LSTV as compared to the ligament on the contralateral side. In patients with bilateral LSTVs, no difference in the iliolumbar ligament compared to that in controls was seen. Developmental changes in the iliolumbar ligament may further exacerbate the altered lumbosacral biomechanics seen in patients with unilateral LSTV, whereas bilateral LSTVs may still allow normal development of the ligament complex. Further research should be done to examine the discrepancies seen in this study.

Percutaneous cryoablation (PCA) is a minimally invasive technique that has been recently used to treat spinal metastases with a paucity of data currently available in the literature. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Prospective or retrospective studies concerning metastatic spinal neoplasms treated with current generation PCA systems and with available data on safety and clinical outcomes were included. In the 8 included studies (7 retrospective, 1 prospective), a total of 148 patients (females = 63%) underwent spinal PCA. Tumors were located in the cervical (3/109 [2.8%], thoracic (74/109 [68.8%], lumbar (37/109 [33.9%], and sacrococcygeal (17/109 [15.6%] regions. Overall, 187 metastatic spinal lesions were treated. Thermo-protective measures (e.g., carbo-/hydro-dissection, thermocouples) were used in 115/187 [61.5%] procedures. For metastatic spinal tumors, the pooled mean difference (MD) in pain scores from baseline on the 0-10 numeric rating scale was 5.03 (95% confidence interval [CI]: 4.24 to 5.82) at a 1-month follow-up and 4.61 (95% CI: 3.27 to 5.95) at the last reported follow-up (range 24-40 weeks in 3/4 studies). Local tumor control rates ranged widely from 60% to 100% at varying follow-ups. Grade I-II complications were reported in 9/148 [6.1%] patients and grade III-V complications were reported in 3/148 [2.0%]) patients. PCA, as a stand-alone or adjunct modality, may be a viable therapy in appropriately selected patients with painful spinal metastases who were traditionally managed with open surgery and/or radiation therapy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Objective: Excessive stress and motion at the L5-S1 level can lead to degenerative changes, especially in patients with posterior instrumentation suprajacent to L5. Attention has turned to utilization of L5-S1 anterior lumbar interbody fusion (ALIF) to stabilize the lumbosacral junction. However, questions remain regarding the effectiveness of stand-alone ALIF in the setting of prior posterior instrumented fusions terminating at L5. The purpose of this study was to assess the biomechanical stability of an L5-S1 ALIF with increasing lengths of posterior thoracolumbar constructs., Methods: Seven human cadaveric spines (T9-sacrum) were instrumented with pedicle screws from T10 to L5 and mounted to a 6 degrees-of-freedom robot. Posterior fusion construct lengths (T10-L5, T12-L5, L2-5, and L4-5) were instrumented to each specimen, and torque-fusion level relationships were determined for each construct in flexion-extension, axial rotation, and lateral bending. A stand-alone L5-S1 ALIF was then instrumented, and L5-S1 motion was measured as increasing pure moments (2 to 12 Nm) were applied. Motion reduction was calculated by comparing L5-S1 motion across the ALIF and non-ALIF states., Results: The average motion at L5-S1 in axial rotation, flexion-extension, and lateral bending was assessed for each fusion construct with and without ALIF. After adding ALIF to a posterior fusion, L5-S1 motion was significantly reduced relative to the non-ALIF state in all but one fused surgical condition (p < 0.05). Longer fusions with ALIF produced larger L5-S1 motions, and in some cases resulted in motions higher than native state motion., Conclusions: Posterior fusion constructs up to L4-5 could be appropriately stabilized by a stand-alone L5-S1 ALIF when using a nominal threshold of 80% reduction in native motion as a potential positive indicator of fusion. The results of this study allow conclusions to be drawn from a biomechanical standpoint; however, the clinical implications of these data are not well defined. These findings, when taken in appropriate clinical context, can be used to better guide clinicians seeking to treat L5-S1 pathology in patients with prior posterior thoracolumbar constructs.

Objective: Patient complaints are associated with a number of surgical and medical outcomes. Despite high rates of patient complaints regarding spine surgeons and efforts to study patient complaints across medicine and surgery, few studies have analyzed the complaints of patients undergoing spinal surgery. The authors present a retrospective analysis that, to their knowledge, is the first study to directly investigate the complaints of spine surgery patients in the postoperative period., Methods: Institutional records were reviewed over a 5-year period (2015-2019) to identify patients who underwent spine surgery and submitted a complaint to the institution's ombudsman's office within 1 year of their surgery. A control group, comprising patients who underwent spine surgery without filing a complaint, was matched to the group that filed complaints by admission diagnosis and procedure codes through propensity score matching. Patient demographic and clinical data were obtained by medical record review and compared between the two groups. Patient complaints were reviewed and categorized using a previously established taxonomy., Results: A total of 52 patients were identified who submitted a complaint after their spine surgery. There were 56 total complaints identified (4 patients submitted 2 each) that reported on 82 specific issues. Patient complaints were most often related to the quality of care received and communication breakdown between the healthcare team and the patient. Patients who submitted complaints were more likely to be Black or African American, have worse baseline health status, and have had prior spine surgery. After their surgery, these patients were also more likely to have longer hospital stays, experience postoperative complications, and require reoperation., Conclusions: Complaints were most often related to the quality of care received and communication breakdown. A number of patient-level demographic and clinical characteristics were associated with an increased likelihood of a complaint being filed after spine surgery, and patients who filed complaints were more likely to experience postoperative complications. Improving communication with patients could play a key role in working to address and reduce postoperative complaints. Further study is needed to better understand patient complaints after spine surgery and investigate ways to optimize the care of patients with risks for postoperative complaints.

Objective: The direct lateral approach is an alternative to the transoral or endonasal approaches to ventral epidural lesions at the lower craniocervical junction. In this study, the authors performed, to their knowledge, the first in vitro biomechanical evaluation of the craniovertebral junction after sequential unilateral C1 lateral mass resection. The authors hypothesized that partial resection of the lateral mass would not result in a significant increase in range of motion (ROM) and may not require internal stabilization., Methods: The authors performed multidirectional in vitro ROM testing using a robotic spine testing system on 8 fresh cadaveric specimens. We evaluated ROM in 3 primary movements (axial rotation [AR], flexion/extension [FE], and lateral bending [LB]) and 4 coupled movements (AR+E, AR+F, LB + left AR, and LB + right AR). Testing was performed in the intact state, after C1 hemilaminectomy, and after sequential 25%, 50%, 75%, and 100% C1 lateral mass resection., Results: There were no significant increases in occipital bone (Oc)-C1, C1-2, or Oc-C2 ROM after C1 hemilaminectomy and 25% lateral mass resection. After 50% resection, Oc-C1 AR ROM increased by 54.4% (p = 0.002), Oc LB ROM increased by 47.8% (p = 0.010), and Oc-C1 AR+E ROM increased by 65.8% (p < 0.001). Oc-C2 FE ROM increased by 7.2% (p = 0.016) after 50% resection; 75% and 100% lateral mass resection resulted in further increases in ROM., Conclusions: In this cadaveric biomechanical study, the authors found that unilateral C1 hemilaminectomy and 25% resection of the C1 lateral mass did not result in significant biomechanical instability at the occipitocervical junction, and 50% resection led to significant increases in Oc-C2 ROM. This is the first biomechanical study of lateral mass resection, and future studies can serve to validate these findings.

Background Context: Bertolotti Syndrome is a diagnosis given to patients with lower back pain arising from a lumbosacral transitional vertebra (LSTV). These patients can experience symptomatology similar to common degenerative diseases of the spine, making Bertolotti Syndrome difficult to diagnose with clinical presentation alone. Castellvi classified the LSTV seen in this condition and specifically in types IIa and IIb, a "pseudoarticulation" is present between the fifth lumbar transverse process and the sacral ala, resulting in a semi-mobile joint with cartilaginous surfaces.Treatment outcomes for Bertolotti Syndrome are poorly understood but can involve diagnostic and therapeutic injections and ultimately surgical resection of the pseudoarticulation (pseudoarthrectomy) or fusion of surrounding segments., Purpose: To examine spine and regional injection patterns and clinical outcomes for patients with diagnosed and undiagnosed Bertolotti Syndrome., Design: Retrospective observational cohort study of patients seen at a single institution's tertiary spine center over a 10-year period., Patient Sample: Cohort consisted of 67 patients with an identified or unidentified LSTV who were provided injections or surgery for symptoms related to their chronic low back pain and radiculopathy., Outcome Measures: Self-reported clinical improvement following injections and pseudoarthrectomy., Methods: Patient charts were reviewed. Identification of a type II LSTV was confirmed through provider notes and imaging. Variables collected included demographics, injection history and outcomes, and surgical history for those who underwent pseudoarthrectomy., Results: A total of 22 out of 67 patients (33%) had an LSTV that was not identified by their provider. Diagnosed patients underwent fewer injections for their symptoms than those whose LSTV was never previously identified (p = 0.031). Only those diagnosed received an injection at the LSTV pseudoarticulation, which demonstrated significant symptomatic improvement at immediate follow up compared to all other injection types (p = 0.002). Patients who responded well to pseudoarticulation injections were offered a pseudoarthrectomy, which was more likely to result in symptom relief at most recent follow up than patients who underwent further injections without surgery (p < 0.001)., Conclusions: Undiagnosed patients are subject to a higher quantity of injections at locations less likely to provide relief than pseudoarticulation injections. These patients in turn cannot be offered a pseudoarthrectomy which can result in significant relief compared to continued injections alone. Proper and timely identification of an LSTV dramatically alters the clinical course of these patients as they can only be offered treatment directed towards the LSTV once it is identified., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: We present a "Do-It-Yourself" method to build an affordable augmented reality heads-up display system (AR-HUD) capable of displaying intraoperative images. All components are commercially available products, which the surgeons may use in their own practice for educational and research purposes., Methods: Moverio BT 35-E smart glasses were connected to operating room imaging modalities (ie, fluoroscopy and 3D navigation platforms) via a high-definition multimedia interface (HDMI) converter, allowing for continuous high-definition video transmission. The addition of an HDMI transmitter-receiver makes the AR-HUD system wireless., Results: We used our AR-HUD system in 3 patients undergoing instrumented spinal fusion. AR-HUD projected fluoroscopy images onto the surgical field, eliminating shift of surgeon focus and procedure interruption, with only a 40- to 100-ms delay in transmission, which was not clinically impactful., Conclusions: An affordable AR-HUD capable of displaying real-time information into the surgeon's view can be easily designed, built, and tested in surgical practice. As wearable heads-up display technology continues to evolve rapidly, individual components presented here may be substituted to improve its functionality and usability. Surgeons are in a unique position to conduct clinical testing in the operating room environment to optimize the augmented reality system for surgical use., (This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2021 ISASS.)

Objective: On August 31, 2017, the state of Ohio implemented legislation limiting the dosage and duration of opioid prescriptions. Despite the widespread adoption of such restrictions, few studies have investigated the effects of these reforms on opioid prescribing and patient outcomes. In the present study, the authors aimed to evaluate the effect of recent state-level reform on opioid prescribing, patient-reported outcomes (PROs), and postoperative emergency department (ED) visits and hospital readmissions after elective lumbar decompression surgery., Methods: This study was a retrospective cohort study of patients who underwent elective lumbar laminectomy for degenerative disease at one of 5 hospitals within a single health system in the years prior to and after the implementation of the statewide reform (September 1, 2016-August 31, 2018). Patients were classified according to the timing of their surgery relative to implementation of the prescribing reform: before reform (September 1, 2016-August 31, 2017) or after reform (September 1, 2017- August 31, 2018). The outcomes of interest included total outpatient opioids prescribed in the 90 days following discharge from surgery as measured in morphine-equivalent doses (MEDs), total number of opioid refill prescriptions written, patient-reported pain at the first postoperative outpatient visit as measured by the Numeric Pain Rating Scale, improvement in patient-reported health-related quality of life as measured by the Patient-Reported Outcomes Measurement Information System-Global Health (PROMIS-GH) questionnaire, and ED visits or hospital readmissions within 90 days of surgery., Results: A total of 1031 patients met the inclusion criteria for the study, with 469 and 562 in the before- and after-reform groups, respectively. After-reform patients received 26% (95% CI 19%-32%) fewer MEDs in the 90 days following discharge compared with the before-reform patients. No significant differences were observed in the overall number of opioid prescriptions written, PROs, or postoperative ED or hospital readmissions within 90 days in the year after the implementation of the prescribing reform., Conclusions: Patients undergoing surgery in the year after the implementation of a state-level opioid prescribing reform received significantly fewer MEDs while reporting no change in the total number of opioid prescriptions, PROs, or postoperative ED visits or hospital readmissions. These results demonstrate that state-level reforms placing reasonable limits on opioid prescriptions written for acute pain may decrease patient opioid exposure without negatively impacting patient outcomes after lumbar decompression surgery.

Background: The goal of this study was to identify predictors of prolonged operative time (OT) in patients receiving posterior/transforaminal lumbar interbody fusion (P/TLIF) and examine the relationship between prolonged OT and perioperative outcomes in this population., Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried for patients undergoing single-level P/TLIF (Common Procedural Terminology code) between 2012 and 2018. Multivariable linear regression models were constructed to identify factors independently associated with changes in OT and examine the relationship between prolonged OT and perioperative outcomes (overall complications, surgical complications, medical complications, 30-day readmission, 30-day reoperation, and length of stay). All models were adjusted for sociodemographic variables, comorbidities, and procedure-specific variables., Results: Our cohort included 6260 patients. After adjusting for baseline covariates, age between 19 and 39 years increased OT by 15.14 minutes, male sex increased OT by 12.91 minutes, African American race increased OT by 17.82 minutes, other race increased OT by 18.13 minutes, obesity class III increased OT by 27.80 minutes, and the use of navigation increased OT by 10.83 minutes. Our multivariate logistic regression also found that after 2 hours, each additional hour of OT was associated with an increased risk of any complication (3-3.99 hours, odds ratio [OR], 1.68; 4-4.99 hours, OR, 2.33; and >5 hours, OR, 4.65). Incremental increases in OT were also associated with an increased risk of extended length of stay, readmission, and return to the operating room., Conclusions: The results of this study highlight several factors associated with prolonged OT and underscore its association with poorer perioperative outcomes. These data can be used to risk stratify patients before single-level P/TLIF., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Osteobiologics are engineered materials that facilitate bone healing and have been increasingly used in spine surgery. Autologous iliac crest bone grafts have been used historically, but morbidity associated with graft harvesting has led surgeons to seek alternative solutions. Allograft bone, biomaterial scaffolds, growth factors, and stem cells have been explored as bone graft substitutes and supplements., Objective: To review current and emerging osteobiologic technologies., Methods: A literature review of English-language studies was performed in PubMed. Search terms included combinations of "spine," "fusion," "osteobiologics," "autologous," "allogen(e)ic," "graft," "scaffold," "bone morphogenic protein," and "stem cells.", Results: Evidence supports allograft bone as an autologous bone supplement or replacement in scenarios where minimal autologous bone is available. There are promising data on ceramics and P-15; however, comparative human trials remain scarce. Growth factors, including recombinant human bone morphogenic proteins (rhBMPs) 2 and 7, have been explored in humans after successful animal trials. Evidence continues to support the use of rhBMP-2 in lumbar fusion in patient populations with poor bone quality or revision surgery, while there is limited evidence for rhBMP-7. Stem cells have been incredibly promising in promoting fusion in animal models, but human trials to this point have only involved products with questionable stem cell content, thereby limiting possible conclusions., Conclusion: Engineered stem cells that overexpress osteoinductive factors are likely the future of spine fusion, but issues with applying viral vector-transduced stem cells in humans have limited progress., (© Congress of Neurological Surgeons 2021.)

Study Design: This was a retrospective consecutive cohort analysis., Objective: This study aimed to examine the association between commonly prescribed medications and outcomes following posterior lumbar spine surgery., Summary of Background Data: Postoperative complications and prolonged length of stay significantly increase costs following posterior lumbar spine surgery and worsen patient outcomes. To control costs and complications, providers should focus on modifiable risk factors, such as preoperative medications. Antihypertensive and anticholinergic drugs are among the most commonly prescribed medications but can carry significant risks in the perioperative period., Materials and Methods: This study was a retrospective cohort analysis of patients undergoing posterior lumbar spine surgery from January 2014 through December 2015 at a large tertiary care center. The variable selection followed by multivariable logistic and negative binomial regressions were performed. An α threshold of 0.0056 was used for significance after correction for multiple comparisons. A secondary analysis was performed to evaluate confounding or effect modifying variables., Results: This study included 1577 patients. Postoperative urinary retention risk was increased in patients taking loop diuretics. Acute kidney injury risk was increased for patients on nondihydropyridine calcium-channel blockers. Surgical site infection risk was increased for patients on aldosterone receptor blockers. Urinary tract infection risk was increased for patients on anticholinergics for urinary incontinence. Length of stay was decreased for patients on angiotensin II antagonists and angiotensin-converting enzyme inhibitors., Conclusion: A care path should be established in the perioperative period for patients who are deemed to be at higher risk due to medication status to either modify medications or improve postoperative monitoring., Level of Evidence: Level III., Competing Interests: M.P.S. receives royalties from Zimmer Biomet and acts in a consulting role to Globus and Intellirod. The remaining authors declare no conflict of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

The spine is a frequent site of cancer metastasis leading to intractable pain, functional impairment, and poor quality of life. When analgesic regimens and nonpharmacological interventions fail, spine surgery may be indicated. For patients with advanced disease, the decision to operate can become a dilemma. A patient with colon cancer metastatic to his spine, who had undergone multiple procedures for back pain, was admitted to a palliative care unit, where pain persisted despite high-dose opioids and adjuvant analgesics. Owing to progressive disease, he was told of a prognosis of six months by his oncologist. He eventually underwent percutaneous pedicle screw fixation. Shortly after surgery, he settled on a regimen merely equivalent to 45 mg of morphine per day. The article explores the role of palliative spine surgery in managing intractable cancer-related back pain. The authors offer a guide when considering surgical procedures for patients with limited prognosis.